Posture detection systems or head tracking systems are used in aeronautics, notably to detect head posture, for fighter helmets and for military, civilian or para-civilian helicopter helmets. The last-mentioned case of para-civilian applications may involve sea rescue missions for example. They are also used for simulation helmet detection, and this detection can then be combined with an oculometry device, also called eyetracker, to detect the position of the gaze. In the virtual reality and gaming field, there are also numerous applications for these systems.
More generally, in the field of generic posture detection, there are also numerous applications, notably in the medical field for remote operations and instrument control, in the field of position control for servocontrolled machine tools, or remote control, and finally for cinema, in order to reproduce movements in computer-generated images.
Currently, aeroplane and helicopter pilots use a so-called “lip lamp” or “lip light” to read a map or enter information on the keyboard of their mission system. Cockpit lighting devices are generally discrete so as to ensure safety for the aircraft and the pilot, notably in reconnaissance missions for example. In the case of military helicopters flying at very low altitude, night-time stealth is critical and any lighting that might be visible from outside is forbidden.
The lip light is fixed to the arm of the headset microphone, and has a control switch activated by the pilot by means of a slight pressure of the lips and of the tongue. Thus, the pilot can keep his hands on the flight controls.
The power supply for this lamp is generally produced by a battery installed in or on the helmet. Lighter devices exist which have a small accumulator powered by the microphone circuit.
The position of the lamp is adjusted by the pilot at the start of the mission so as to orient the light flux and place the switch close to the lips.
The lamp often comprises one or more LEDs, possibly LEDs of different colours, compatible or not compatible with the light intensifying night vision devices.
The intensity of the lighting can be adjusted by selecting the number of active LEDs or by virtue of a potentiometer. White LEDs give a more natural view of the environment and some are compatible with light-intensifying devices.
Operationally, the pilot operates his lip light when he looks at the interior of the cockpit and must switch it off to look outside with complete stealth.
After a number of “operations” or actions on the lip light switch, the arm of the microphone supporting the lamp is displaced. Said arm can shift slightly with each use.
The pilot therefore often has to readjust it in flight, which constitutes a nuisance and a risk of flight safety.
Moreover, the pilot often has to alternate his gaze between the outside of the cockpit and the interior, and one drawback lies in the large quantity of equipment present in a cockpit, notably multifunction screens, and the adequacy of the lighting for the equipment being viewed.
Given the context in which the pilot is greatly occupied, said pilot does not spontaneously adapt the lighting, for example its intensity, to the equipment that is viewed.